A typical icemaker mounted in the freezer compartment of a domestic refrigerator will make about one harvest of cubes per hour. The typical icemaker includes a timing motor, a valve for admitting water into the ice mold to form ice, a thermostatic switch in thermal communication with the ice mold, a heater for partially melting the ice so that it will release from the mold, and an ejector bar with fingers for ejecting cubes from the mold.
A typical harvest cycle begins with the timing motor running. During a water fill period defined by the motion of the timing motor, a predetermined quantity of water flows into the mold. After the mold is filled to the desired level, the timing motor shuts off, initiating a freezing period. The ice freezing period ends when the thermostatic switch changes state, indicating that the water has frozen to ice. The thermostatic switch turns the timing motor on. The motion of the timing motor turns the heater on and rotates the ejector bar until the fingers contact the ice. The timing motor then stalls in this position, the stall torque of the motor putting continued pressure on the ice in the mold. As soon as the heater has sufficiently melted the ice to release it from the mold, the fingers begin moving and eject the ice from the mold and into the storage bin.
Once ice has been ejected into the bin, a feeler mechanism associated with the bin generates a signal to initiate a new cycle and form more ice if the bin is not full.
Despite numerous prior units, there are certain difficulties with known icemakers. In particular, known icemakers have complex designs with a multiplicity of parts, particularly in the switching elements, increasing cost and reducing reliability. Furthermore, known icemakers require the use of stallable motors which are more expensive than non-stallable motors. Also, to perform an installation test of an existing icemaker, an installer must manually advance the switch timing mechanisms, which can require uncomfortable and difficult manipulation and increases the likelihood of damage to the icemaker during installation.
Thus, it is an object of the invention to provide a simplified icemaker with fewer parts and greater reliability, particularly in the switching mechanisms.
Further, it is an object of the invention to provide an icemaker in which the need for a stallable timing motor is eliminated.
Further, it is an object of the invention to provide an icemaker having an improved installation testing procedure.